That's not to say that everywhere can (and should) speak English. When you travel off the beaten path, you'll discover that the simplest act such as ordering food becomes an adventure if you can't speak the local language. That being said, if you stay on the main drag and visit the places meant for tourists, English is your best bet.
Haedong Yonggungsa Temple, Busan, South Korea
Busan is the exception.
We went out one night to an international party. It was hosted at a cafe that during the day, offers a language exchange of sorts with local university students and foreigners. On Friday nights, though, it turns into a party. Thanks to its prime location between two Universities, its proximity to our hostel, and the all-you-can-drink beer for about $12, it was the perfect chance to meet some locals.
Our table was mostly Koreans. There were a few guys who were in the Air Force. They spoke Korean and some knew a bit of English. The girls, though, were all Japanese majors at one of the universities and spoke fluent Japanese... but no English. Guess what language we were speaking in most of the night?
In all seriousness, though, it was the best Japanese practice I've had during my time in Japan (well, in Asia). When the common language is no one's first language, there's no cheating by switching into your first. It also matters less when you make mistakes. Since neither of you are native speakers, you understand the other's difficulty with learning the language and feel less pressured to be perfect.
No joke--I spoke more Japanese in Korea than in Japan
Throughout the trip, Japanese trumped English numerous times. At Jagalchi fish market, we gorged on Korean sashimi. Our server started taking our order in English, but as soon as he realized that we spoke Japanese, he switched over since it was more comfortable for him.
The first night, we were playing beer pong with a Korean couple. We struggled to communicate with them in English as the guy only spoke a little, but his girlfriend couldn't at all. After one disastrous turn, Yannick and I were cursing at each other in Japanese. Instantly, they both switched to Japanese, and after that point, the conversation flowed smoothly.
At Burger King, the cashier struggled to understand my order of a cheeseburger and fries but as soon as Yannick ask for his order of フライドポテト, she took his order perfectly, even though the menu is written in Korean... and English.
It was such an eye-opening experience. Don't get me wrong--I've always believed that foreign languages are important. It shows interest in the country's culture to speak their language. However, I never thought that knowing any foreign language (foreign to them, not to me) could be more useful than English. For example, if I went somewhere, I wouldn't get by with French. Outside of countries that used French as an official language, the chances to use French decrease dramatically. English is much more likely to be spoken (ex. Take Vietnam, a former French colony. The only time I found French useful was talking to a French guy once. It never once helped me speak to a local).
Yet, Busan proved me wrong. It was the first place that English lost to another foreign language in terms of practicality and number of speakers. As I continue traveling, I'm sure it won't be my last.
And though I hate the idea of returning to the same place more than once, Busan may have to be the exception...